An ultrasonic endoscope system (2) is provided with an endoscope processor (14) for producing an endoscopic image from an image signal obtained through a CCD (12), and an ultrasonograph processor (15) for producing an ultrasonographic image from an echo signal received on an ultrasonic transducer (13). The processors (14, 15) are connected to a peripheral equipment control unit (16) through USB, and the peripheral equipment control unit (16) is connected to peripheral equipments (19) through USB. The peripheral equipment control unit (16) consists of a CPU (30) and three USB controllers (31, 32, 33) for controlling the USB connections to the processors (14 , 15) and the peripheral equipments (19) individually. The peripheral equipment control unit (16) operates as a host to the peripheral equipments (19), and as a device to the respective processors (14, 15). The processors (14, 15) are connected to a filing device (25) through Ethernet, and to a movie recorder (26) through IEEE1394 bus.
